Bridgeway Bible Dictionary 
Yahweh, or Jehovah, was the personal name of God by which the Israelites knew him as their God – and their God was the one and only true God ( Exodus 4:22; Exodus 32:27; Deuteronomy 6:4; 1 Samuel 17:45). When they wanted to name a place after some special event where they had seen God at work, they often formed the name by combining God’s name with a suitable Hebrew word ( Genesis 22:8; Genesis 22:14; Exodus 17:15; Judges 6:24; Ezekiel 48:35). They also combined shortened forms of Yahweh (Jehovah) with other words to form names for people ( 2 Kings 11:1-2; 2 Kings 11:4; 2 Kings 11:21).
Usage in Hebrew
The word ‘Jehovah’ probably never existed in the Hebrew language. Originally Hebrew was written with consonants only, the readers supplying the vowels as they read. The word from which ‘Jehovah’ comes consists of the consonants YHWH, and was probably pronounced ‘Yahweh’. Transliterations of the word in other languages support this as the likely pronunciation.
Absolute certainty, however, is not possible, as there are no Hebrew records old enough to preserve the original pronunciation. By the time written Hebrew had established the practice of adding vowels to the consonants, the Jews no longer spoke the name YHWH. They claimed this was because of their reverence for God’s name, but for many it was more because of superstition. Whatever the reason, the practice became universal that when Jews read the Scriptures, instead of speaking the word YHWH, they substituted the word adonai, meaning ‘lord’ or ‘master’.
When, about 300 BC, a new version of the Hebrew Bible added vowels to the consonants for the first time, it put the vowels of adonai to the consonants YHWH. This resulted in the word ‘Jehovah’, though the Jews continued to substitute the word adonai for YHWH when speaking. Many English versions of the Bible have avoided the pronunciation problem by using the expression ‘the LORD’ (in capital letters) for YHWH. (See also Jesus CHRIST, sub-heading ‘Jesus as Lord’.)
Meaning of the name
Both the origin and the meaning of the name Yahweh are uncertain. Abraham, Isaac and Jacob knew God by his name Yahweh ( Genesis 15:7; Genesis 26:24-25; Genesis 28:20-21), though they did not understand its full significance. They knew that God was the creator of the universe, the one who controlled all things and was able to fulfil the promises he had made to them, but they did not live to see those promises fulfilled ( Genesis 15:5-6; Genesis 15:13-15).
Several hundred years later, when God was about to bring the descendants of these men out of slavery in Egypt, God’s people were given a fuller understand of the significance of the name Yahweh. Yahweh was their God according to the covenant he had made with Abraham, and now he would save them according to that covenant ( Genesis 15:18; Exodus 2:24; Exodus 3:16). In other words, Yahweh was more than just a covenant God; he was a covenant redeemer. In making himself known to the Israelite slaves as a redeemer, Yahweh was showing a characteristic of himself that Abraham, Isaac and Jacob had never seen ( Exodus 6:2-8).
Although the events of Israel’s salvation from Egypt displayed Yahweh’s character, the meaning of the name was still mysterious. The name YHWH was connected with the Hebrew words ‘I am’. God gave no simple explanation of what his name meant, but he reassured his people by stating his name in words that may be translated ‘I am who I am’ or ‘I will be what I will be’. Yahweh revealed himself as the one who is eternal, absolute, unchangeable, always active, always present, and answerable to no one. He would be to his people whatever he chose to be, and they were to trust that he would never fail them ( Exodus 3:13-14; see also God ).
Other names of God
Besides referring to God by his personal name Yahweh, the Bible refers to him by the ordinary Hebrew words for ‘God’ such as El, Elohim and related words ( Genesis 1:1; Joshua 3:10). These words were used even for false gods ( Genesis 31:30; Exodus 15:11). Sometimes El was joined to other words to form more descriptive titles, such as El Elyon, the Most High God ( Genesis 14:18) and El Shaddai, God Almighty ( Genesis 17:1; Genesis 28:3; Genesis 35:11). Anyone, Hebrew or otherwise, might acknowledge the great creator and all-powerful ruler of the universe as God (El), but the Hebrews added to this that El was Yahweh ( Genesis 14:19; Genesis 14:22; Deuteronomy 4:24; Deuteronomy 6:4; Deuteronomy 6:20).
As with Yahweh, El and Elohim were sometimes used when naming places after memorable experiences ( Genesis 21:33; Genesis 28:19; Genesis 32:30; Genesis 33:20). They were used also in names given to people ( Genesis 28:2; Exodus 31:2; 1 Samuel 1:20).
Baker's Evangelical Dictionary of Biblical Theology 
See Names Of God
Fausset's Bible Dictionary 
(See Jah ; JEHOVAH.)
Webster's Dictionary 
Alt. of Jahve